Sealed redox battery

A redox battery, comprising:

• a first half cell comprising a positive electrolyte reservoir comprising a first electrolyte contacting a positive electrode and having dissolved therein a first redox couple configured to undergo a first redox half reaction;
• a second half cell comprising a negative electrolyte reservoir comprising a second electrolyte contacting a negative electrode and having dissolved therein a second redox couple configured to undergo a second redox half reaction;
• an ion exchange membrane separating the positive electrolyte reservoir and the negative electrolyte reservoir,
• wherein the first half cell, the second half cell and the ion exchange membrane defining a redox battery cell are sealed in a casing,
• wherein neither of the positive electrolyte reservoir nor the negative electrolyte reservoir of the redox battery cell is connected to a separate electrolyte tank storing a respective one of the first or second electrolytes;
• and
• a pressure relieving structure comprising a pressure relief conduit directly connecting the positive electrolyte reservoir and the negative electrolyte reservoir,
• wherein the pressure relieving structure is con figured to reduce or at least partly prevent a pressure buildup in one or both of the positive electrolyte reservoir and the negative electrode reservoir during operation by controllably mixing the first and second electrolytes.